Background-subtracted 0.5–10 keV XMM-Newton/EPIC-pn light curve of 2022 outburst of SAX J1808 measured using 200 s-long bins. A red band indicates the low-flux interval, and a blue band shows the interval of the HST observation discussed in this paper (see Sect. 3.2 for details). Two Type I X-ray bursts, detected at 59831.87 and 59832.82 MJD, are not plotted. Green dash-dotted lines indicate the epochs of their occurrence.